Featured Research

from universities, journals, and other organizations

No map, no problems for monarchs

Date:

April 8, 2013

Source:

University of Guelph

Summary:

Monarch butterflies have long been admired for their sense of direction, as they migrate from Canada and the United States to Mexico. According to new findings from a team of scientists, the winged insects fly without a map, and use basic orientation and landmarks to find their way to their wintering sites, thousands of miles away.

Monarch butterflies have long been admired for their sense of direction, as they migrate from Canada and the United States to Mexico. According to new findings from a team of scientists, including researchers from the University of Guelph, the winged insects fly without a map, and use basic orientation and landmarks to find their way to their wintering sites, thousands of miles away.

Related Articles

Recently published in the Proceedings of the National Academy of Sciences, the study examined the insects' flight patterns and whether those patterns changed when the butterflies were displaced.

The team, which included researchers from Queen's University, Germany and Denmark, also analyzed more, also analyzed more than 50 years' worth of migration data to learn how monarchs find their way for the first time to their wintering habitat in Mexico.

A monarch flies the full migration route just once during its life cycle.

The flight patterns and data suggest that, when butterflies are blown off course, they likely use major geographic landmarks to funnel them to their destination.

Looking at the distances that these insects fly each year, scientists had long thought that monarchs were "true navigators."

"To be a true navigator, you need both a compass and a map," explained Prof. Ryan Norris, Department of Integrative Biology. "We've know for some time that monarchs use external cues, such as the sun and magnetic field, as a built-in compass that can indicate their latitude. But having an internal map requires knowledge of both latitude and longitude."

To test whether monarchs could detect longitude displacements, the team, led by U of G undergraduate student Rachael Derbyshire, examined the butterflies' flight patterns in a funnel on the University of Guelph campus. They then tested the same monarchs in Calgary.

"The monarchs we tested in Guelph flew southwest, in the general direction of Mexico," said Derbyshire. "When we tested them in Calgary, they flew in the same general direction as if they were in Ontario, suggesting that they did not know they had been displaced 2,500 kilometres."

Studying data from monarchs tagged and recaptured throughout North America from 1952 to 2004, the team found that migrating monarchs do not use an internal map to reach Mexico. Instead, they use landmarks, such as coastlines and the Rocky and Appalachian mountains.

"Given the challenge of this migratory journey and the fact that these insects are less than a gram, it is a remarkably simple system they used to travel thousands of kilometres to a site they have never seen," said Norris.

Monarchs use the same sites in the highlands of central Mexico each year. One mystery remains: how do they pinpoint these exact locations in Mexico?

Derbyshire said, "One possibility we think is likely, and would need to be tested, is that they -- like some other migratory animals -- use smell to guide them to their final destination."

Henrik Mouritsen,
Rachael Derbyshire,
Julia Stalleicken,
Ole Ø. Mouritsen,
Barrie J. Frost,
and D. Ryan Norris. An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators. Proceedings of the National Academy of Sciences, 2013; DOI: 10.1073/pnas.1221701110

Mar. 31, 2015 — Using the assessment tool ForWarn, US Forest Service researchers can monitor the growth and development of vegetation that signals winter's end and the awakening of a new growing season. Now these ... full story

Mar. 31, 2015 — Until now electric fences and trenches have proved to be the most effective way of protecting farms and villages from night time raids by hungry elephants. But researchers think they may have come up ... full story

Mar. 31, 2015 — Researchers have detected a human fingerprint deep in the Borneo rainforest in Southeast Asia. Cold winds blowing from the north carry industrial pollutants from East Asia to the equator, with ... full story

Mar. 31, 2015 — A team of engineers and biologists reports new progress in using computer modeling and 3D shape analysis to understand how the unique grasping tails of seahorses evolved. These prehensile tails ... full story

Mar. 31, 2015 — As the five-year anniversary of the explosion of the Deepwater Horizon oil rig approaches, a new report looks at how twenty species of wildlife are faring in the aftermath of the ... full story

Mar. 31, 2015 — Scientists have uncovered the earliest fossilized evidence of an insect caring for its young. The findings push back the earliest direct evidence of insect brood care by more than 50 million years, ... full story

Mar. 31, 2015 — New research has scientists re-thinking how a lethal fungus grows and kills immune cells. The study hints at a new approach to therapy for Candida albicans, one of the most common causes of ... full story

Mar. 31, 2015 — The most virulent strains of Streptococcus suis, the leading cause of bacterial meningitis in adult humans in parts of southeast Asia and in pigs around the world, are likely to have evolved and ... full story

Mar. 31, 2015 — Darwin's evolutionary theory predicts survival of the fittest. So why do different survival tactics co-exist, if evolution should always favor the winning strategy? To answer that question scientists ... full story

Bionic Ants Could Be Tomorrow's Factory Workers

Reuters - Innovations Video Online (Mar. 30, 2015) — Industrious 3D printed bionic ants working together could toil in the factories of the future, says German technology company Festo. The robotic insects cooperate and coordinate their actions and movements to achieve a common aim. Amy Pollock reports.
Video provided by Reuters

Lions Make Surprise Comeback in Gabon

AFP (Mar. 30, 2015) — Lions have made a comeback in southeast Gabon, after disappearing for years, according to live footage from US wildlife organisation Panthera. Duration: 00:32
Video provided by AFP

Related Stories

Mar. 19, 2014 — Monarch butterflies may be named for their large size and majestic beauty, but once again their numbers are anything but king-sized. In fact, 2014 may go down as one of the worst years ever for the ... full story

Feb. 21, 2013 — Each fall millions of monarch butterflies migrate south in order to escape frigid temperatures, traveling up to 2,000 miles to an overwintering site in a specific grove of fir trees in central ... full story

Mar. 19, 2012 — New research reveals how monarchs recolonize the northern reaches of their breeding grounds -- information that will help preserve this migratory species threatened by loss of critical food and ... full story

Mar. 1, 2011 — Despite recent cold snaps that brought record-setting low temperatures over much of Texas, the outlook for the annual Monarch butterfly invasion to the state looks promising "and better than ... full story

July 26, 2010 — Some North American monarchs born in the Midwest and Great Lakes fly directly west over the Appalachians and settle along the eastern seaboard. This finding is the first proof of longitudinal ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.